Jobs failed metric is incremented multiple times when a job is cancelled

This issue takes place when a job is cancelled, and the cancelled counter is incremented (correctly as expected), then the JobExecutor issues cleanup tasks for this cancelled job with a status of FAILED, leading the execution of these cleanup tasks to also increment the failed job counter (due to the FAILED status).

We need to keep track of what job id has been stat-collected already, and not update the stats anymore on any follow up tasks for that specific job id.